A balloon rubbed against the head can be both a hair-raising and a hair-tearing experience, a new study suggests. Clumps of balloon and hair invisible to the naked eye may break off each object during contact and stick to the other.

The existence of this exchange could challenge traditional theories about how static electricity builds up, a process known as contact electrification.

“The basic assumptions people have made about contact electrification are wrong,” says Bartosz Grzybowski, ...